Michael, who's in his thirties, is an insurance agent, appreciated by his superiors for his methodical work. But behind the smooth facade lurks a dangerous pedophile who kidnapped a 10-year-old boy named Wolfgang several months earlier. Michael keeps him in the basement of his suburban home, where he's installed a vault. There the child spends all his time, except for a few evenings watching TV or a trip to the zoo. To minimize risks, Michael keeps his neighbors, colleagues and family members away. Finally, during his tormentor's absence, the boy tries a desperate maneuver to escape.